1. Field of the Invention
The invention disclosed herein is a ventilation, air diversion, and dust control system for primary use with longwall shearer mining machinery, but can also be applied in situations where air diversion is necessary for the control of contaminants, and other airborne matter.
2. Description of the Prior Art
In longwall mining operations, such as coal mining, dust control and ventilation are critical to maintenance of machine operator safety. During mining operations, dust and harmful gas concentrations are generated, and if uncontrolled, will generally flow into the vicinity of the operator, thus creating a health hazard. Under current methods, removal of airborne matter such as dust and methane gas generated during mining operations is accomplished by either spraying the working area or under more complex procedures, by including in addition to a fluid spray, the inducement of an air flow that diverts the dust and gas away from the areas where it may accumulate. Examples of prior art which spray the working area with a dust suppressing medium are taught in U.S. Pat. No. 4,084,855 (R. C. Miles et al), and U.S. Pat. No. 2,693,950 (A. W. Calder). Examples of prior art which also include induced air flow as an additional means of dust suppression include U.S. Pat. No. 4,157,204 (F. N. Kissell et al) and U.S. Pat. No. 3,333,896 (J. J. Diamanti).
It has been taught that water sprays will induce air flow in the direction of the spray. U.S. Pat. No. 4,157,204 (F. N. Kissell et al) and U.S. patent application Ser. No. 870,162, Jan. 17, 1978, entitled "Ventilation System for Continuous Mining Machines," by F. N. Kissell and R. E. Wallhagen, describe in detail the use of fluid sprays to induce air flows. However, the prior art has concentrated on inducing air flow toward the front of the machine from the rear, across the working face, and then toward the rear on the side away from the operator to dilute the methane gas at the front of the machine. A different problem arises in longwall mining when there is a need to confine the dust cloud rather than forcing air forward to dilute gas. In longwall mining operations, the circular flow pattern characteristic of prior art will not be effective, and simply spraying the working face will not prevent significant amounts of dust from flowing into the area occupied by the machine operators.
The subject invention addresses this problem by providing a system whereby the fresh airstream approaching the machine is split into two separate portions, so that one portion flows to the area occupied by the operator while the other portion is directed by fluid sprays away from the operator, toward the working face and the longwall and thereafter on past the rear of the mining machine. These sprays also increase ventilation by inducing additional air flow across the longwall face as well as suppressing the amount of dust generated during the mining operation.